A known electric power steering apparatus includes a torque sensor, which detects steering torque, and an electric motor which drives a vehicle steering member in accordance with the steering torque detected by the torque sensor. The output shaft of the electric motor and the vehicle steering member are typically drivingly coupled by a worm gear and worm wheel. The worm gear and worm wheel have meshing gear teeth.
Wear of the meshing gear teeth of the worm gear and worm wheel causes clearance between the meshing teeth. Such clearance is undesirable. Accordingly, adjustment mechanisms for controlling such clearance are known.